ul {
  list-style: none;
  padding: 0;
}

header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 10px;
  margin-bottom: 10px;
}

header nav ul {
  display: flex;
}

header nav ul li {
  margin-right: 20px;
}

header nav ul li:last-child {
  margin-right: 0;
}

header nav ul li a {
  color: #fff;
  text-decoration: none;
}

main {
  display: grid;
  grid-template-columns: 80% 20%;
}

.cards {
  display: grid;
  grid-template-columns: 30% 30% 30%;
  grid-gap: 20px;
  padding: 0;
}

.cards li {
  border: 5px solid #000;
}

.cards h2 {
  margin: 0;
  padding: 10px;
  background-color: #333;
  color: #fff;
}

.cards .inner {
  padding: 10px;
}

aside {
  padding: 10px;
}

@media (max-width: 980px) {
  header {
    flex-direction: column;
    align-items: start;
    padding: 0;
  }

  header .title {
    padding: 20px;
    font-size: 30px;
  }

  header nav {
    width: 100%;
  }

  header nav ul {
    display: block;
    margin: 0;
  }

  header nav ul li {
    display: block;
    width: 100%;
    padding: 15px 20px;
    border-bottom: 1px solid #eee;
  }

  header nav ul li:last-child {
    border-bottom: none;
  }

  main {
    display: block;
  }

  .cards {
    display: grid;
    grid-template-columns: 100%;
    grid-gap: 20px;
    padding: 0;
  }
}